The correct answer for the function of photoreceptor cells involved in color vision in human eyes is option 2: Cones.

Photoreceptor cells are specialized cells found in the retina of the eye that are responsible for detecting and converting light into electrical signals that can be interpreted by the brain as vision. There are two types of photoreceptor cells: rods and cones.

Option 1: Rods are responsible for our ability to see in low light conditions and are not directly involved in color vision. They are mainly responsible for detecting shades of gray.

Option 3: The blind spot refers to the area on the retina where the optic nerve exits the eye. This area does not contain any photoreceptor cells, so no light perception occurs here.

Option 4: The fovea is a small depression in the retina that contains a high concentration of cones. It is responsible for our most detailed vision, but it is not directly involved in color vision itself.

In summary, cones are the photoreceptor cells that are primarily responsible for color vision in human eyes.